The best response that highlights the differing views of J. Edgar Hoover and Joseph McCarthy regarding communism is:
Hoover used surveillance to identify suspected traitors. McCarthy used hearings.
This response distinguishes Hoover's methods, which involved the FBI's surveillance and intelligence gathering tactics, from McCarthy's approach, which was characterized by high-profile public hearings aimed at exposing alleged communists and communist sympathizers within the U.S. government and other sectors.